Radial inflow gas turbine engines may have a turbine that uses an impeller to receive combustion gases from combustors and associated conventional transition ducts. The combustion gases rotate the impeller as the impeller directs the flow of combustion gases from a radially inward direction to an axial direction. Due to the nature of combustors and conventional transitions the combustion gases may be properly oriented by a first row of vanes disposed between an outlet of the conventional transition duct and the impeller. The first row of vanes may also accelerate the combustion gases to an appropriate speed. Such configurations with conventional transitions and a first row of turbine blades add cost, complexity, and reduce efficiency of the engine. Consequently, there remains room in the art for improvement.